Archive for October, 2010

You know the “out of Africa” story: how our ancestors left the savannas where humanity grew up and trekked outward to other continents. Today in Nature, however, a new study of 40 million-year-old fossils argues that an “into Africa” story predates the other narrative: that the animals that would eventually evolve into apes like us and monkeys came from Asia into Africa.

These fossil teeth found in Libya belong to early anthropoids, according to the scientists. The team found several different species in this location.

The new fossils are about 38 to 39 million years old, and none of the animals would have weighed more than 500 grams [just more than 1 pound], conclude a team led by Jean-Jacques Jaeger, a palaeontologist at the University of Poiters, France. Their diminutive size fits in with previous research suggesting that early anthropoids started small and eventually evolved ever bigger bodies. [Nature]

Deep in your brain there are probably several thousand neurons that will respond only to the sight of Lady Gaga. Several thousand others probably only crackle to the sight of Justin Bieber. It might be nice to reassign those neurons to loftier thoughts. For now, though, neurology can’t help you. What neurology can do for you (if you’re up for a little invasive brain surgery) is let you use those Gaga and Bieber neurons to control a computer.

A team of researchers has built on the previous discovery that specific neurons respond to the images of specific people–like Lady Gaga, or your grandmother. To harness these neurons, the researchers tried out an ingenious brain-machine interface based on images of celebrities who triggered particularly strong responses in 12 patients.

A patient could bring a digital image of a celebrity (like Marilyn Monroe) into the foreground by consciously focusing on the image, which meant that the celebrity-associated neurons were firing. As they describe in a paper in Nature, the patients quickly got the hang of it, activating patches of neurons at will. This has led researchers to wonder if people could one day control devices simply by visualizing certain people, things, or concepts.

You can get the rest of the story on this fascinating but intrusive technology, and can also see a video that Carl made about the experiments, at The Loom.

For DARPA, the secretive military research agency, it’s not enough for a prosthetic limb to simply resemble a normal one, or for a patient to be able to move it through some remote control. DARPA-backed engineers are attempting to build a system in which peripheral nerves would be reattached to artificial limbs, which could send signals to a brain sensor that could reply. This would be a vast improvement over prosthetics that require conscious directives, and could turn a prosthetic into something that responds the way an ordinary limb would.

Darpa’s after a prosthetic that can record motor-sensory signals right from peripheral nerves (those that are severed when a limb is lost) and then transmit responding feedback signals from the brain. That means an incredibly sensitive platform, “capable of detecting sufficiently strong motor-control signals and distinguishing them from sensory signals and other confounding signals,” in a region packed tightly with nerves. Once signals are detected, they’ll be decoded by algorithms and transmitted to the brain, where a user’s intended movements would be recoded and transmitted back to the prosthetic. [Wired.com]

According to the team behind the system at Johns Hopkins University’s Applied Physics Laboratory, tests on monkeys have shown that the primates have remarkable success controlling a prosthesis through a cortical chip implanted in their brains, and researchers have undertaken some human tests. What remains to be seen, though, is how much dexterity people can get through this process.

For most insects, walking onto a spider’s web and disturbing the sticky threads would be a very bad idea. The distinctive vibrations of wriggling prey only serve to draw the spider closer and inevitably ends in the insect getting bitten, wrapped in silk and digested. But this story doesn’t always unfold in the spider’s favour. Some vibrations aren’t made by helpless prey, but by an assassin lurking on the web.

The assassin bug (Stenolemus bituberus) is a spider-hunter. Sometimes, it simply sneaks up to spiders on their own webs before striking, plunging its dagger-like mouthparts into its prey. But it also has a subtler technique. Sitting on the web, it plucks the silken threads with its legs, mimicking the frequency of weakly struggling prey. These deceptive vibes are an irresistible draw to the spider, who rush towards their own demise.

We know things are bad for biodiversity. But just how bad across the board? The scientists at the International Union for Conservation of Nature, as they will from time to time, just updated their Red List—an accounting of how much trouble vertebrate species face. According to them, one in five around the world is threatened, and the numbers are worse for groups like sharks and amphibians.

The survey results, which are coming out in the journal Science, are based on research conducted in nearly 40 countries. The 174 scientists studied about 25,000 species to estimate the condition of the approximately 56,000 species on the Red List. From IUCN’s release:

“The ‘backbone’ of biodiversity is being eroded,”says the emminent American ecologist and writer Professor Edward O. Wilson, at Harvard University. “One small step up the Red List is one giant leap forward towards extinction. This is just a small window on the global losses currently taking place.”

On November 4, NASA’s mission EPOXI will make a flyby less than 450 miles from the comet Hartley 2. Here’s what to know about this dirty snowball.

1. It’s a frequent visitor.

Malcolm Hartley discovered this namesake comet 24 years ago, and it’s returned to swing around the sun a few times since.

Like the famous Halley’s Comet, Comet Hartley 2 is a periodic comet that follows a years-long loop around the sun. It takes 6.46 years to complete one circuit, compared with Halley’s 75.3 years. [Christian Science Monitor]

During an unusual bureaucratic meeting yesterday, members of California’s Occupational Safety and Health Administration sat down with representatives of California’s porn industry to talk about safe sex.

Last year, the AIDS Healthcare Foundation filed a petition asking Cal/OSHA to tighten health regulations on the porn industry. And the issue was brought to the fore this month when an adult-film performer tested positive for HIV, which brought several porn production studios to a halt while the industry scrambled to determine the source of the infection and to test the performer’s partners.

At yesterday’s meeting, Cal/OSHA officials went over the existing rules, which were originally written to protect health care workers and were only later applied to porn performers. The rules require employers to protect their employees against blood-borne pathogens via “barrier protection,” which in the hospital world probably means rubber gloves, face masks, and the like. In the porn industry, the obvious protective measure would be requiring male performers to wear condoms, but in straight films that hasn’t come to pass (in gay films, condoms are standard).

After decades of development, Iran’s first nuclear power plant is close to operational. This week the country’s TV service announced that engineers have begun loading the fuel rods into the core of the Bushehr plant in southern Iran.

The 1,000-megawatt Bushehr plant has been under construction since before Iran’s 1979 Islamic Revolution. It was first contracted to a company that later became German industrial giant Siemens; more recently work was done with the help of Russia’s state-owned atomic energy company. [Los Angeles Times]

The days of blasting off into the temporary weightlessness of suborbital space are fast approaching—for people with the right stuff in their bank accounts, anyway. Some scientists fear, though, that once the space tourism business becomes established, a steady train of people hurtling into euphoria at the borderline of space could have climactic consequences down here on the surface.

They’re talking about soot. Soot or black carbon, which comes from fuel that does not burn completely, ought to be a more high-profile climate villain than it is, and it would be easier to contain than the carbon dioxide emissions we’re more worried about. According to a team led by Martin Ross, craft flying at such great heights would leave a trail of soot that wind and weather patterns could not reach, leaving it to hang around there and interfere with climate patterns. They published their model (paper in press) of this scenario in Geophysical Research Letters.

Ross’ team presumed 1,000 suborbital flights a year by a decade from now, and plugged in the estimated emissions to see what would happen. They modeled all the flights as coming over Spaceport America, the Virgin Galactic-backed New Mexico spaceport.

A huge bounty of amber unearthed in India is giving researchers a peak at the wildlife that inhabited the area 50 million years ago, via the insects that are trapped inside it. The findings, published in the Proceedings of the National Academy of Sciences, suggest that the Indian subcontinent was not as isolated as previously thought.

“We know India was isolated, but … the biological evidence in the amber deposit shows that there was some biotic connection,” says David Grimaldi, curator in the Division of Invertebrate Zoology at the [American Museum of Natural History]. [Press release]

About 150 million years ago, the Indian tectonic plat separated from the African plate and began its 100 million year journey to Asia. During that long journey the subcontinent was isolated from all other continents, giving its wildlife the chance to evolve in distinctly different ways (much like the evolution of marsupials in Australia). Since the amber was deposited in the form of sticky tree resin 50 million years ago, it gives researchers insight into the insects that were adrift on the subcontinent.

“The amber shows, similar to an old photo, what life looked like in India just before the collision with the Asian continent,” says Jes Rust, professor of Invertebrate Paleontology at the Universität Bonn in Germany. “The insects trapped in the fossil resin cast a new light on the history of the sub-continent.” [Press release]